Methylphenidate hydrochloride (HCl) and dexmethylphenidate hydrochloride both have the empirical formula C14H19NO2.HCl. Methylphenidate HCl is a racemic mixture of d,1-threo-methyl α-phenyl-2-piperidineacetate hydrochloride. Several commercial products, including, e.g., Ritalin®, Daytrana™, and Metadate™ contain methylphenidate HCl as the active drug. Dexmethylphenidate is the d-threo-enantiomer of racemic methylphenidate hydrochloride [Focalin® product literature]. There are several commercial products which contain dexmethylphenidate as the active drug.
The use of the central nervous system stimulants methylphenidate and dexmethylphenidate for the treatment of such conditions as attention deficit disorder (ADD) and attention deficit hyperactivity disorder (ADHD) in adults and children has been described [see, Focalin®, Concerta®, Ritalin®, Daytrana™ and Metadate® product literature]. This drug may also be used to treat depression and cognitive impairment following Traumatic Brain Injury [See, product literature for methylphenidate hydrochloride tablet which is commercially available from Lake Erie Medical DBA Quality Care Products LLC, and product literature of the other drug products identified herein].
Solid dose extended release methylphenidate or dexmethylphenidate products are commercially available. These products include, e.g., Focalin® XR, Concerta®; Ritalin® LA, and Metadate®. However, to applicant's knowledge, there is no commercially available extended release liquid product containing a methylphenidate.
The methylphenidate based medications are predominantly prescribed for children, including children as young as 3 years old where they have difficulty, swallowing the solid dosage forms. There remains a need for a stable, long-acting liquid methylphenidate product which can be conveniently delivered in an oral, titratable formulation.